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Double Bubble for use in Floor Joist, Basement, Radiant Floor, Tiny Home/Yurt, Crawl Space, Metal Building, and Cathedral Ceiling applications

Floor Joist Insulation - 16" x 125' (166.63 sq. ft.)

Floor Joist Insulation - 16" x 125' (166.63 sq. ft.)

SKU: EF2222-16-125

Install under floor joists and radiant floor heating systems

Regular price $89.00
Regular price Sale price $89.00
Sale Sold out


EcoFoil Floor Joist Insulation is constructed of a double layer of polyethylene bubble insulation bonded to two radiant barrier metalized sheets. This (1/4" to 5/16") thick insulation provides superior protection against radiant heat transfer and also provides an effective vapor barrier, preventing condensation which can cause mold. Bubble insulation is rated by its high reflectivity of 96%, and low emissivity of 4%. This means only 4% of radiant heat passes through the insulation. Simply put the insulation is not trying to slow the way heat passes through it, the insulation is trying to eliminate heat from passing through it.

This insulation is designed to fit in between either a studded wall or floor joists that are 16" on center. The 16" wide insulation is lightweight and includes a 3/4" flat staple tab on each side for easy installation.

R-Value Of Radiant Barriers

Rather than rating by R-value, all radiant barrier products are measured by their reflective and emissive properties. EcoFoil double bubble insulation is 96% reflective and 4% emissive, meaning the product only allows 4% of radiant heat to pass through. 

There are some companies out there posting big R-Value numbers for their radiant barriers, but those numbers are rating the entirety of the system—including the product, air gap, and other building materials. In reality, most radiant barriers by themselves have little to no R-Value. If you need to satisfy a building code of a specified R-Value, we recommend the use of a traditional insulation in conjunction with our radiant barrier in order to meet code. For more information on R-values, see our How It Works page or contact a member of our friendly service team via chat, by calling (888) 349-3645, or using the form here.  


Ecofoil Floor Joist insulation is made from a double layer of polyethylene bubbles, sandwiched between two highly reflective surfaces with a metabolized coating. Pre-cut to 16” or 24” width. Staple tabs on both edges allow easy attachment to joists or wall studs. This product is classified as Class 1/Class A in accordance with the ASTM-E84-09 fire test standard. The product was mounted in accordance to ASTM-E2599-08. It is lightweight, durable, and is easy to handle and install.ounted in accordance to ASTM-E2599-08. It is lightweight, durable, and is easy to handle and install.

Shipping Info:

EcoFoil ships free via FedEx Ground. Products ship same-day on orders received before 4pm CT and typically arrive between 1-4 days. Expedited shipping options available. Call us at 888.849.3645 or contact us for more information on shipping options.


16 in x 125 ft (167 square feet per roll)

~1/4" thick

Installation Tips:

Convenient staple taps along each edge make for easy installation under floor joists or between wall studs.

Spec Sheets:

Download Spec Sheet
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Customer Reviews

Based on 24 reviews
patricia langdon
Awesome product

Amazing product. Easy to use. I am 57yr lady and did my crawl space w ekectric stapeler. Its ready 4 cold.

Reed Johnson


David B. Horton

Quick service and a reliable product

mark perry

It's all good. Worked out well

Thomas Okma

Great product could use a larger staple flange

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